NASA just announced that their pair of spacecraft known as Stereo have, as of January 22, 2009, reached “quadrature.” The twin satellites were launched two years ago, and each used the moon as a gravitational slingshot to move itself either ahead or behind earth while maintaining the same solar orbit. (There are graphs of this on Stereo’s page at NASA). “Quadrature” has occurred now as the satellites are 90 degrees apart from one another (45 degrees away from the earth, each). NASA has also announced that in 2011, the instruments will be 180 degrees apart, giving us a complete and simultaneous view of the entire surface of the sun for the first time ever. Scientists jokingly refer to the opposite side of the sun that we cannot see from earthbound solar observatories as the “dark side,” although it’s obviously not dark at all.
While waiting for 2011 and a 3D holographic near-real time model of the sun, take a look at the stunning videos of the sun’s surface captured by the Stereo satellites, available in a variety of formats and compression levels from NASA’s Stereo homepage. I tried to repost one of their videos of a solar eclipse as seen by Stereo, but I couldn’t get it in the same quality as the quicktime version. There are dozens more beautiful videos in the gallery of solar prominence eruptions, coronal mass ejections, a solar tsunami, even a comet losing its tail to a solar hurricane. Oh, and there’s a 3D video gallery, too.